Antigua and Barbuda is a constitutional monarchy and a Commonwealth realm, with Queen Elizabeth II as its reigning monarch since 1 November 1981. As such she is Antigua and Barbuda's sovereign and officially called Queen of Antigua and Barbuda.

Most of the Queen's powers in Antigua and Barbuda are exercised by the Governor-General, though the Monarch does hold several powers that are hers alone.

The Queen is the only member of the Antiguan and Barbudian Royal Family with any constitutional role; she, her husband, Prince Philip, Duke of Edinburgh, their son The Prince of Wales, and other members of the Royal Family, including the Queen's other children and cousins, undertake various public ceremonial functions within Antigua and Barbuda and abroad.